Meson mT-scaling in heavy-ion collisions at SIS energies

We perform systematical studies on transverse-mass spectra of π0, η, ω, φ, K+ and K− mesons for C+C, Ni+Ni, Au+Au collisions at SIS energies within the HSD transport approach. We find that the mT-spectra sensitively reflect the in-medium properties of the mesons. The ʹbare massʹ scenario leads to a general scaling behaviour for the meson mT-spectra when including a mass shift due to the associate strangeness production threshold for kaons and antikaons whereas a ʹdroppingʹ mass scheme violates this mT-scaling. The relative slope parameters, however, provide valuable information about the average meson potentials in the nuclear medium.